One unit of this type is known from EP 1 167 247 B 1. It comprises at least two essentially cylindrical conveyor rollers that are aligned parallel to one another, longitudinally in the direction of conveyance of the articles. The conveyor rollers are capable of rotating around their longitudinal axes, and each conveyor roller comprises an integrated conveyor belt that rotates around the said roller. The top run of each conveyor belt is essentially aligned on the circumferential surface of the conveyor rollers, which in the region of the top run of the conveyor belts is recessed. To enable the longitudinal transport of the containers, the conveyor rollers are tilted toward one another such that the two top runs of the conveyor belts form a V-shaped channel, in which the container lies. Containers are transported longitudinally until they reach an identification unit, which is designed to scan data on the container, for example a barcode on its outer surface. The identification unit is ordinarily positioned above the path of conveyance or to its side. Because the circumferential surfaces of the containers lie in random positions once the containers have been loaded into the unit, the barcode may not lie within the scanning range of the identification unit. In such cases it is necessary to rotate the container. This is accomplished by means of a unidirectional rotation of the conveyor rollers, which causes the conveyor belts integrated into said rollers also to rotate. Once the distinguishing markings on the container have been scanned, the conveyor rollers reassume a position in which the top runs of the conveyor belts form a V-shaped channel. By actuating the conveyor belts, the container is then advanced in a longitudinal direction for further processing or is conveyed in a reverse direction if it is identified as a container that cannot be accepted by the system.
Another unit of this type is disclosed in EP 1 081 661 A 2. This unit comprises two conveyors that are essentially identical in design; these are comprised of conveyor elements and are tilted toward one another so as to form a V-shaped channel. Between the transport elements, slots are provided extending transversely to the longitudinal direction of conveyance. Beneath the two conveyors, rotational discs are arranged, extending over at least a portion of the length of the conveyors, in which discs can be raised so that they protrude through the slots in the transport elements. When this function is activated, a container lying on the conveyors is lifted off the conveyors by the rotating discs. The container then rests on the rotating discs and can be placed in rotation via the unidirectional actuation of the rotating discs. As in the above case, this allows an obscured identifying mark on the container, such as a barcode, to be scanned by an identification unit.